Vending machine

ABSTRACT

The vending machine includes a plurality of product carriers mounted for free-swinging movement on one or more elongated endless conveyors. Carrier leveling means at the top and bottom of the conveyor loop maintains the carriers in substantially horizontal orientation as they are moved about the ends of the conveyor loop from one vertical run to the other. The contents of the carriers are passed in front of and discharged through an opening in the vending machine cabinet in which one or more transparent windows are mounted for vertical sliding movement. Each window may be urged toward its closed position by means of a spring biased rhombic frame.

United States Patent 1 3,697,148 Weber 5] Oct. 10, 1972 [54] VENDING MACHINE 2,632,925 3/1953 Long et al ..49/405 Inventor: W b 1 1 Manchester Parsons X M y' Simpan 3,287,074 11/1966 Crossley ..3l2/97 [22] F|ledz Dec. 29, 1969 2| A N 43 Primary Examiner.iames T. McCall 1 pp 0 9 AttorneyPendleton, Neuman, Williams & Anderson [52] US. Cl. ..3l2/268, 198/140, 312/91, [57] ABSTRACT [5|] Int CL Ji 3S The vending machine includes a plurality of product [58] Field 36 138 carriers mounted for free-swinging movement on one 312/139 151 b a or more elongated endless conveyors. Carrier leveling 221/13 27 '|55 222/344 means at the top and bottom of the conveyor loop {6/71 72 49/405 3 maintains the carriers in substantially horizontal orientation as they are moved about the ends of the conveyor loop from one vertical run to the other. The [56] References cued contents of the carriers are passed in front of and NI D STATES PATENTS discl'lilarged bthrough 2111111 hopening in the vending mac ine ca inet in w 'c one or more transparent 511,208 12/ i893 Nilson ..49/40$ windows are mounted for vertical sliding movemenL 795,979 8/1905 Hopkins ..3 12/97 Each window may be urged toward its cloud position :Z'Z by means of a spring biased rhombic frame. 2,030,741 2/1936 Bodine ..3 12/268 33 Claim, 24 Drawing Figures 3? k a W I! /6 164 was- /z 1 5 C i; -7 o o o 166 11 r r X5 i,- 2 i 5 9 Q? Hill.

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PATENIED I97? 3. 697. 148

sum 1 or 4 PATENTEU B 1019?? 3.697.148

saw 3 OF 4 fir? VENDING MACHINE BACKGROUND OF THE INVENTION This invention relates to a vending machine and more particularly a vending machine of the type having a plurality of article carriers which are sequentially moved to a discharge position on an endless conveyor. In this type of a machine the carriers or article-holding devices are usually mounted for free swinging movement so that they will always remain in a substantially horizontal product-holding position as they are moved around the closed loop of the endless conveyor. Due to friction or uneven loading, however, the free swinging carriers may tend to tip and drop their contents, particularly as the portions of the conveyor to which they are connected change direction at the top and bottom ends of a generally vertically elongated conveyor loop. The present invention features a novel means for maintaining the horizontal attitude or orientation of the carriers, even when they are moving about the ends of the conveyor loop from one vertical run to the other.

Another feature of the invention is the delivery door and display window combination which permits the customer to see the article that he is purchasing and the machine is dispensing and permits the customer to compare that article with other articles in the vending machine.

The desirability of a display window in a vending machine has long been recognized. At the present time, however, in those vending machines where the display window is large enough to reveal a number of the articles in the machine, it is usually not possible to view the very article which is being purchased, for usually a separate door or chute is provided for this purpose. In some cases the window is an individual window which also serves as a delivery door, however, in this type of machine it is not possible to view any of the other articles in the machine. The combined delivery door display window of the present invention overcomes these shortcomings, facilitating more flexibility in the vending arrangements and in the cabinet styling.

In certain types of vending machines, particularly those employing refrigeration units, it is desirable to have the delivery doors well sealed to prevent air leakage. This may be accomplished by means of a coil spring which forces the door to a closed position; however, if a coil spring is employed for this purpose, the spring usually will exert the greatest force when the door is open and the least force when it is closed. This is exactly opposite to what is most desirable in a vending machine. The delivery door of a vending machine should be easy to hold open while the customer is removing his purchased product from the machine. Once closed, however, there should be sufficient closing force to obtain an efficient seal against the leakage of air around the door. The present invention solves this problem with a mechanism which exerts smaller force on the door when it is open than when it is closed.

SUMMARY OF THE INVENTION In one form of the invention a vending machine is provided having a cabinet with a viewing and discharge opening. Inside the cabinet is an endless conveyor means which is movable about a vertical closed loop including a pair of spaced substantially vertical runs, one of which passes in front of the cabinet opening. A plurality of product carriers are connected to the conveyor means for free swinging pivotal movement about horizontal axes, these product carriers being sequentially indexed to a discharge location in front of the cabinet opening. Carrier leveling means is provided for maintaining the product carriers in substantially horizontal orientation as they are moved about the ends of the conveyor loop from one vertical run to the other.

A transparent viewing window, which serves the dual function of a delivery door, is mounted on the cabinet for movement between a closed position wherein the window substantially closes the cabinet opening, and an open position wherein access is provided to the interior of the product carrier which is in the discharge location. Stop means is provided for limiting the vertical movement of the window so that when the window is opened, the opening will give access to the interior of only one of the carriers. If desired, the carriers may be suitably partitioned, and the stop means may be made adjustable so that only a certain portion of the carrier will be accessible when the window is open.

Locking means may be provided for each of the windows, with means provided for unlocking a selected one of the locking means so that a selected one of the windows may be opened to give access to the carrier which is in discharge position on the conveyor associated with that window.

The window may be urged toward its closed position by means of a mechanism consisting of at least one, and preferably two of hingedly interconnected pairs of arms. One of the arms of each pair is pivotally connected to the cabinet above the opening and the other armof each pair is pivotally connected to the window. The arms are angularly disposed with respect to each other (i.e., at an angle of less than in all positions of the window movement. A resilient means such as a spring urges the arms in a direction which will increase the angle between the arms, so that the window is urged toward its closed position. In the preferred structure employing two pairs of hingedly interconnected arms, the hinge angles of the pairs of arms are equal and opposite in all positions of window opening. The two pairs may be interconnected at their ends to form a rhom bic frame.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the invention, reference will now be made to the accompanying drawings wherein:

FIG. 1 is a perspective view of a vending machine embodying the various features of this invention showing one of the windows held in the open position, permitting the vended product to be withdrawn from the carrier which is in the discharge location in front of that window opening;

FIG. 2 is an enlarged perspective view of the vending machine illustrated in FIG. 1, showing the front of the machine open and revealing the interior of the machine, including the arrangement of the product carriers, the windows and the window locks;

FIG. 3 is an enlarged perspective view showing the mounting of one of the windows and further showing the novel means for resiliently urging the window toward its closed position:

FIG. 4 is an enlarged perspective view of a portion of the vending machine showing the conveyor means, the product carriers, and the mechanisms for maintaining the carriers in their horizontal position as they are :noved around the top and bottom ends of the conveyor oop',

FIG. 4a is a sectional view of the apparatus illustrated in FIG. 4 taken substantially along line 4a --I4a of that figure;

FIG. 5 is a perspective view of the follower employed in connection with the carrier leveling mechanism illustrated in FIG. 4;

FIG. 6 is a side elevational view of a portion of the apparatus showing a novel drive mechanism for the conveyor;

FIG. 7 is a front elevational view of the top portion of the apparatus showing a mechanism for driving the conveyor and the mechanism for leveling the carriers at the top loop of the conveyor;

FIGS. 8, 9 and 10 are side elevational views of portions of the carrier leveling mechanism, illustrating these portions of the mechanism in various positions as the carriers are moved around the top loop of the conveyor;

FIGS. ll, 12 and 13 show various modifications in the design of the product carriers; FIG. 11 showing a carrier which is open at the top and both front and back sides; FIG. 12 showing a carrier which is closed at its backside and provided with a horizontal partition dividing the carrier into two compartments; and FIG. 13 showing a carrier which is divided by a vertical partition into two laterally adjacent compartments;

FIG. 14 is an enlarged perspective view of a portion of the vending machine showing a carrier leveling mechanism of modified construction;

FIGS. 15 and I6 schematically illustrate the carriers and parts of the carrier leveling mechanism of FIG. 14 in two different positions assumed as the carriers are moved about the top loop of the conveyor;

FIG. 17 is an enlarged perspective view of a portion of the vending machine showing a carrier leveling mechanism of further modified construction;

FIG. 18 is a front elevational view of the portion of the apparatus illustrated in FIG. 17;

FIG. 19 is a perspective view of the follower employed in connection with the carrier leveling mechanism illustrated in FIGS. 17 and 18;

FIG. 20 is an enlarged side elevational view of the gears of the carrier leveling mechanism illustrated in FIGS. 17 and 18; and

FIGS. 21, 22 and 23 schematically illustrate the carriers and parts of the carrier leveling mechanism of FIGS. 17 and 18 in three different positions assumed as the carriers are moved about the top loop of the conveyor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With further reference to the drawings and particularly to FIG. I there is shown a vending machine having a boxlike cabinet 32 of usual construction and provided with a door 34. The door is hinged along one side and has a lock 36 at the other so that the door may be swung open to the position illustrated in FIG. 2 for servicing and filling. The particular apparatus illustrated in the drawings is adapted to be serviced entirely from the front. It will be appreciated, however, that in some installations the apparatus may be serviced from the rear, in which case a rear door may be provided in addition to or in place of the front door 34.

The front door 34 of the vending machine cabinet has an opening 38 through which the articles carried by the vending machine may be viewed and dispensed. The opening 38 in the door is closed by means of a window assembly 40 which in the illustrated embodiment comprises five separately operable windows 40a, 40b, 40c, 40d and 40e, the details of which will be more fully hereinafter described.

Within the interior of the vending machine 30 is an article-handling mechanism 42 which in the preferred embodiment comprises five separate, identically constructed article-handling units 42a, 42b, 42c, 42d and 42a. In FIG. 4 one of the article-handling units 420 has been removed from the vending machine cabinet. This unit includes a frame 44 consisting of four L-shaped upstanding corner bars 46, 48, 49 and 50. A pair of dust panels 51 and 52, respectively, cover the top and bottom of the frame, and a plurality of transversely extending vertically spaced bracing plates 54a, 54b, 54c and 54d extend between the corner bars 48 and 49 on one side of the frame, with correspondingly positioned bracing plates 54a, 54b, 54c and 54d extending between the corner bars 46 and 50. This construction leaves the front and back portions of the frame open except for the flanges of the corner bars 46-50.

As best illustrated in FIG. 4a, two intermediate panels 56 and 58 may be disposed centrally within the frame, these panels being held in place by means of L- shaped brackets 59, 60, 61 and 62. The vertical panels 56 and S8 divide the frame into two ductlike sections 63 and 64. The intermediate panels are somewhat shorter than the frame 44, with the top and bottom ends of the panels being spaced from the top and bottom end plates 51 and 52.

Extending through and journaled for rotation within the oppositely-disposed top braces 54a and 54a is a horizontal shaft 66, and a parallel horizontal shaft 68 extends through and is journaled for rotation in the transverse bottom braces 54a and 54d. Keyed to the shaft 66 are two sprockets and 72, best illustrated in FIG. 7. The sprocket 70 is disposed closely adjacent the transverse brace 54a, and the sprocket 72 is disposed closely adjacent the transverse brace plate 540'. A similar pair of sprockets are keyed to the shaft 68 in vertical alignment with the top pair of sprockets. The bottom sprockets are not shown in the drawings.

Extending about the sprockets are two endless chains 74 and 76 of standard construction. The conveyor chain 74 carries a plurality of uniformly-spaced arms 740, these arms extending outwardly substantially perpendicular to the portion of chain on which they are carried. Thus, in the vertical front and rear portions of the chain run, the arms extend horizontally, and about the sprockets the arms extend radially. A similar set of arms 760 are carried by the conveyor chain 76, and the arms on the two chains are in horizontal registration. Since the sprockets 70 and 72 over which the chains 74 and 76 are trained are keyed to a single shaft, the con veyor chains will remain with their corresponding arms 74a aand 760, respectively, horizontally aligned.

A carrier 78 is mounted for horizontal swinging movement between each pair of arms 74:: and 76a of the two conveyor chains. Each carrier 78 has a pair of vertically-disposed rectangular sides 80 and 81 and at least one horizontal plate or floor 82 extending therebetween. A back wall 83 may also be provided. The pivotal trunnionlike connection of each carrier between the corresponding pair of parallel arms 74a and 76a member is such that the carrier will be permitted to swing freely and will remain in the horizontal position unless unbalanced by some exterior force. The spacing between the arms 74a and 760 on their respective conveyor chains and the height of the vertical walls 80 and 81 of the carriers 78 is preferably such that when the carriers are on the vertical front or rear portions of the run of the conveyor chains, these carriers will be in substantially vertically abutting relationship with one another as best illustrated in FIG. 4.

The sprockets 70 and 72 and the conveyor chains 74 and 76 which are trained thereover are rotated by means of an electric motor which may transmit power through a gear reducer 86 to an output shaft 86a. Mounted on the output shaft 860 is a drive wheel 88 consisting of a round plate 90 having a plurality of horizontally-disposed rollers 92 connected thereto in angularly-spaced (i.e., radially-spaced) relationship. The size and radial spacing of the rollers 92 corresponds with the pitch of the chain and the spacing and size of the teeth on the sprocket 72, such that the rollers 92 on the drive wheel 88 will mesh with the sprocket and, in effect, drive the sprocket. A second or outside plate 94 is preferably employed to stabilize and reinforce the rollers 92 on the roller drive wheel 88. This is best illustrated in FIG. 7. This type of roller wheel-to-sprocket drive is more precise and avoids the backlash and looseness which is inherent in a chain drive due to the slack in the chain. In a vending machine this can be an important factor. The roller drive wheel 88 also has another advantage in that this can drive the sprocket 72 directly without the addition of another sprocket on the shaft 66. Note that the chain 76 is trained over the top of the sprocket 72, and the roller drive wheel 88 drives the sprocket beneath between the front and rear vertical portions of the conveyor chain run.

As the carriers 78 are moved through the front and rear ducts 63 and 64, respectively, of the frame 44, there is little tendency for swinging movement because, as previously stated, the adjacent carriers are in substantial vertical abutment with one another. Moreover, the flanges of the corner bars and the presence of the rear plates 56 and 58 prevent any substantial horizontal movement of the carriers as they are moving vertically. However, when the carriers 78 reach and start to move about the top and bottom ends of the conveyor loop (defined by the chain sprockets) they are beyond the top and bottom extremities of the plates 56 and 58, and they are being moved away from the flanged corner bars of the frame. Also, in this swinging movement at the top and bottom of the conveyor loop, the carriers separate, and they do not again come into substantial abutment with one another until they have been swung from one side of the conveyor run to the other and are again moving vertically. In this transverse swinging movement of the carriers about the ends of the conveyor loop, the conveyor chain is continually changing orientation, but the carriers must remain horizontal It is therefore particularly desirable to provide stabilization for the carriers in these portions of the conveyor run so that there is no tendency toward tilting or tipping such as would permit the contents of the carrier from dropping out.

It is preferred that a carrier leveling means be provided at both the top and bottom loops of the conveyor run for maintaining the carriers 78 in a substantial horizontal orientation during their transverse swinging movement from the one vertical run of the conveyor to the other. One form of the carrier leveling means is embodied in the mechanism 96 illustrated in FIGS. 4 and 5. The mechanism 96 includes a follower 98 which has an elongated vertical shank 100 and a transverse head 102 (see H6. 5). The follower shank 100 has a pair of spaced, axially aligned, elongated slots 103 and 104 with an outwardly protruding stud 105 disposed therebetween. The follower head 102 has an inwardlyextending upper flange portion 106 and an outwardlyextending lower flange portion 107. The follower is mounted with the horizontal flange portion 106 extending inwardly into the path of the movement of the carriers 78 and the horizontal flange portion 107 of the follower extending outwardly.

The outer end of the sprocket shaft 66 extends through the top slot 103 in the follower shank and beneath the outwardly-extending horizontal flange portion 107. A lug 108, which is affixed to the transverse brace 54a in vertical alignment with the sprocket shaft 66, extends through the lower elongated slot 104 in the shank portion. The follower 98 is thus mounted for vertical sliding movement with respect to the frame 44, with the shank 100 maintaining its vertical orientation and the flange portions 106 and 107 their horizontal orientation throughout the movement of the follower. A spring 110, stretched between the lug 108 and the stud 105 on the follower shank portion, urges the follower downwardly.

The flange 106 of the follower is adapted to engage and reciprocally move in the vertical direction with the carriers 78, thereby preventing the carriers from any substantial tilting or tipping as they are swung about the end of the conveyor loop. [t is preferred, however, that the follower be forcibly raised by means other than the carriers themselves. it is also preferred that the inwardly-extending carrier-engaging flange portion 106 be maintained in close proximity to but normally vertically-spaced from the carriers as the carriers are moved about the end of the conveyor loop. in other words, the follower is preferably not in constant engagement with the carriers, but rather, is kept close enough to be engaged by any carrier which begins to tip from the horizontal.

In the embodiment illustrated in FIGS. 4 and 5, the follower moving means includes an operating element 112 having a pair of oppositely disposed, radially-extending arms 113 and 114 which carry rollers 113a and 114a, respectively, adjacent their outer extremities. The rollers 113a and 1140 are, preferably, of a diameter which is greater than the width of the arms 113 and 114, so that even when the element 112 is in its horizontal position as illustrated in FIGS. 4 and 8, the rollers will be in contact with the outwardly-extending flange 107 of the follower. The operating element 112 is keyed or otherwise fixed for rotation on the end of the sprocket shaft 66 so that the element 112 will be rotated simultaneously and at the same rate as the sprockets 70 and 72.

As the element 112 is rotated, the rollers 113a and 1140 on the arms of the element will sequentially engage the outwardly-extending flange 107 of the follower and force the follower upwardly from the position illustrated in FIGS. 4 and 8 through the position illustrated in FIG. 9 and to the position illustrated in FIG. 10. At all times the inwardly-extending flange 106 of the follower is maintained in just slightly spaced relationship with respect to the upper part of the carrier 78. After reaching the position illustrated in FIG. 10, of course, the element 112 continued to rotate and the follower is moved downwardly at the same rate as the carrier under the urging of the spring 1 10.

The start of the cycle of carrier movement about the conveyor loop and of synchronized follower movement begins when a pair of carrier holding arms 74a and 76a reach horizontal alignment with the axis of the sprocket shaft 66. At this point the operating element 112 is also horizontal. Throughout the entire 180 cycle of rotation, the element 112 will remain in precise transverse alignment with the carrier holding arms 74:: and 760.

It will be apparent that for each 180 turn of the sprockets 170 and 172, one of the carriers 78 will be moved from the rear run of the conveyor to the forward run, and the element 1 12 will also be rotated 180 to ef fect reciprocal movement of the follower 102 from its retracted or lowered position illustrated in FIG. 8, through its extended position illustrated in HQ. 10, and back again to its initial or retracted position. The length of the stroke or vertical movement of the follower is governed by the length of the arms 113 and 114 of the operating element, and, of course, the slots 103 and 104 in the shank of the follower will have to be of sufficient length to permit unimpeded movement of the follower.

The carrier leveling mechanism 116 at the bottom of the article handling unit 42a is constructed identically with the upper carrier leveling mechanism 96 just described. Accordingly, the parts of the bottom carrier leveling mechanism have been given the same numbers as those of the upper carrier leveling mechanism 96. The operating element 112 of the bottom carrier leveling mechanism is mounted on and keyed for rotation with the horizontal sprocket shaft 68 and, thus, operates in precisely the same manner as the operating element 112 of the upper carrier leveling mechanism 96. The two carrier leveling mechanisms 96 and 116 operate independently of each other, however, because the rate of vertical movement of the carriers 78 and of the followers is not uniform throughout the cycle. The rate of vertical movement of the followers and carriers will be greatest at the beginning and end of the cycle, i.e., as the carriers leave one run and as they approach the other. The rate of vertical movement will be least at the middle of the cycle as the carriers approach (and leave) the apogee of their movement at the precise top and bottom ends of the conveyor loop. The rate of vertical movement is actually a function of the sine of the angle which the follower-engaging arm of the operating element 112 makes with the horizontal. Both the sine of this angle and the rate of vertical movement decrease as the angle approaches The angular rate of rotation of the operating element 112, of course, remains constant over the 180 cycle. The carriers thus are stabilized in their movement about the various portions of the conveyor run so that each of the products being vended will remain in proper place in their respective carriers until removed during the vending operation.

The carriers may be specially designed to hold particular product shapes or they may be designed merely as a shelf or support for a wide variety of articles. The carriers illustrated and described herein are of this universal or shelf type. However, even these may be varied depending upon the manner in which the vending machine is operated. Regardless of the design, the portions of the carriers 78 which are engaged by the follower or followers are horizontal in their normal, free swinging, stabilized and balanced position.

In FIGS. 4 and 7 the carriers 78 are illustrated as being provided with a back wall 83. if the vending machine is designed for rear loading, it may be desirable to eliminate this back wall. Such a modified carrier 78' is illustrated in FIG. 11. This carrier has only the vertical side walls 80 and 81 and the horizontal shelf or floor 82.

In FIGS. 4 and 7 the carriers are shown as providing only a single product compartment. It may be desirable to further partition the carrier by means of a second horizontal shelf 118 to provide the modified carrier 78" illustrated in FIG. 12. Alternatively, the partitioning or compartmenting may be accomplished by means of a vertical partition forming the carrier 78" illustrated in FIG. 13. If a second horizontal shelf 118 is to be utilized, it may be desirable to make this shelf removable so that the carrier could be used for large as well as small product handling and vending.

In the carrier 78" illustrated in FIG. 13, the carrier is of double width providing a double width floor 82' and a double width rear wall 83'. In a selective" type of vending machine where the mechanism may be actuated to rotate continuously until the item which the customer desires reaches the delivery stage, it may be desirable to provide a carrier of this type. In fact, it may be desirable to have only one large article-handling unit instead of five separate small units as illustrated in the drawings. Of course, to hold the same number of products, the carriers would be five times as wide and divided into five compartments, each serviced by a separate delivery door or window.

In the illustrated vending machine, the contents of the carriers are viewed through and are dispensed through the five windows 40a, 40b, 40c, 40d, and 40:: of the window assembly 40. The five windows correspond to and are aligned with the five article-handling units 42a, b, c, d, and e, respectively. In the forward run of the conveyors for each of the article-handling units, the carriers 78 are moved in close proximity with the corresponding window where their contents may be viewed. The windows 40a-e are also adapted to serve as doors through which the articles or products carried by the carriers 78 may be dispensed.

The windows 40a-e are identically constructed and operated, each comprising a transparent panel 120 which is mounted for vertical sliding movement in the tracks of two vertical double track elements 122 and 124, respectively, as best illustrated in FIG. 2. The height of the transparent window panel 120 is greater than the height of the opening 38 in the door of the vending machine, so that when the window is closed, that portion of the opening 38 will be closed. In the embodiment illustrated in FIGS. 1 and 2, all of the windows are closed, with the exception of window 40d which has been vertically raised to its open position.

The distance or height which the individual windows may be opened (raised) is preferably regulated by means of stops 126 which may be in the form of lugs threaded or otherwise fitted into'apertures 128 in the back side of the door 34. (See FIG. 3.) The positioning of these lugs may be made adjustable so that the height of maximum window opening will be approximately equal to the height of the compartments of the carriers 78. Thus, if the carriers are transversely partitioned by a shelf 118 in the manner illustrated in FIG. 12, the stops 126 may be moved to their lower positions, so that the windows would be only capable of opening half the distance which they could if the stops were in their upper positions. Each window is preferably permitted to open enough so that the interior of one, and only one, carrier 78 (or carrier compartment) is accessible through the window.

While the windows may be returned to their closed positions by means of gravity, in a refrigerated unit where tight sealing is important it is best to have each of the windows held in the closed position by resilient means. A simple spring closing is not desirable because a spring exerts the greatest closing force when the window is being held open by the purchaser, and least closing (and sealing) force when the window is closed.

The window closing mechanism 130 shown in FIGS. 2 and 3 provides the opposite action. This mechanism exerts the greatest closing (and sealing) force when the window is closed and the least when the window is being held open. In the embodiment illustrated in FIG. 2, there are five window closing units 130, one for each of the five windows 40a-e. This mechanism 130 includes four hingedly connected arms 132, 134, 136, and 138. The arms 132 and 134 form one pair of arms which are connected by means of a hinge pin 140, and the arms 136 and 138 form the second pair of arms which are hinged together by means of a hinge pin 142. The arm 132 of the first pair of arms and the arm 138 of the second pair of arms are pivotally connected to each other and to the cabinet door 34 by means of a pin 144. In the same manner the lower arm 134 and the lower arm 136 of the respective pairs of arms are pivotally connected to each other and to the transparent window panel 120 by means of a pin 146. The pivot pins 144 and 146 are vertically aligned, and the arms 132-138 are of equal length so that the hinge pins 140 and 142 are horizontally aligned. The four equal length interconnected arms form an articulated rhombic frame which is movable between an extended position or form shown in solid lines in FIG. 3 and a compressed position or form illustrated in dotted lines in FIG. 3.

It will be noted that in all positions the hinge pins 140 and 142 will remain on their respective sides of the vertical line which bisects the pins 144 and 146 connecting the unit to the cabinet and the panel, respectively. The arms of each hinged pair are thus angularly disposed with respect to each other (i.e., less than 180) in all positions of window movement, and the hinge angles are both opposite and equal.

A resilient spring 148 extends between the hinge pins and 142 to resiliently urge these hinge connections toward each other and toward the line bisecting the pins 144 and 146. Since the arms are always angularly disposed with respect to one another, there will always be a vertical component of force exerted by the combination of the spring 148 and the two pairs of arms 132-134 and 136-138. However, this vertical component of force changes in accordance with the angle between the arms in each pair. With the window panel 120 in the closed position, the hinge angle between the pair of arms 132 and 134 and the hinge angle between the arms 136 and 138 will be the greatest, and the component of vertical force exerted on the window panel 120 will be the greatest. When, however, the window panel is moved to its open or dotted line position as illustrated in FIG. 3, the hinge angles between the arms in the respective pairs will be the smallest, and the component of vertical force exerted on the window panel 120 will be the least.

it will be appreciated that the pairs of arms 132-134 and 136-138 do not have to be pivotally connected to the same pivot points of the cabinet and the window panel, and as a matter of fact in some installations it may be desirable to only employ one pair of arms. It is preferred, however, that the structure illustrated be employed since it is not only desirable to achieve the regulation of the force as indicated, but it is also desirable to have the horizontal components of the forces balanced so that the only force acting upon the window panel 120 is in the vertical direction. If only one pair of arms were employed, the force would not only be in the vertical direction, but would also be in the horizontal direction as well, which under some circumstances may cause the panel to twist and jam. The use of the two opposed pairs formed into a rhombic frame or pantograph is the most desirable, for with such a structure the forces acting in the horizontal direction are exactly balanced.

The bottom position or closed position of the windows 40a-e is governed by the abutment of each of these panels with the sill 150. Each of the transparent panels 120 may have a handle 152 which may be in the form of either a recess or a protuberance facilitating the manual grasping and raising of the panel.

The vending machine 30 may utilize control mechanisms and circuitry which are standard and well known in the art. The machine may be of the first-in first-out" type or of the "selective type previously described. In the first-in first-out arrangement, the carriers 78 are sequentially indexed and emptied. In this type of machine, the carriers which are in the discharge position in line with the top of the sill are empty at the start of the vending cycle and all of the windows 40a-e are free to be lifted. In the selective type, all of the windows would be locked at the start of the vending cycle.

A coin acceptor-rejecting mechanism 156 controls the start of the vending cycle. The vending circuit is armed or actuated when a coin is placed in the mechanism 156 through the slot 154. The machine may have selector buttons 158a-e which, when pushed, ac-

11 7 tivate the electric motor 84 (see FIG. 7) of one of the mechanisms 42a-e to drive the conveyor chains and index the carriers 78 so that the next loaded carrier on that mechanism will move into the discharge position with the bottom thereof in alignment with the top of the sill 150. The merchandise in the carrier may now be withdrawn by raising the window in front of that carrier. The indexing may be completed and the motor 84 de-energized by means of a normally open switch 160 (see FIG. 4) which may be engaged and closed by means of formations on either of the conveyor chains or the carriers. in the illustrated embodiment these formations are the arms 74a on the conveyor chain 74. It will be appreciated that any protruding formation will accomplish the same result, and if the carriers are divided into two or more compartments, it may be desirable to provide additional formations on the chain or on the carriers. Such formations, of course, must not be located in a manner which would interfere with the free swinging movement of the carriers which rotate 360 with respect to the arms 74a and 76a on each trip around the conveyor run. lf desired, the switch 160 may be positioned to engage the carrier shelf or shelves and stop the indexing each time a shelf reaches the level of the sill 150.

if the vending machine is a selective" type, then the selector buttons 158a-e are used to effect operation of the motor 84 of the particular mechanism 42a-e to rotate the conveyor and the carriers 78 on that mechanism continuously until the item which the customer selects reaches the discharge or delivery position. Then by pushing a vend button 170, the solenoid 168 above the selector button which has been pushed will open and unlock the window so that the panel 120 above the selector button may be raised and the contents of the carrier withdrawn. There may be a separate vend button 170 for each viewing and dispensing window.

[n the illustrated embodiment, a locking mechanism 162 is provided for each of the windows 40a-e. Such a locking mechanism may serve as a safety lock and sensing device in a "first-in first-out" arrangement preventing the indexing of the carriers 78 when one of the windows is in a raised position and locking the windows while the carriers are being indexed. A locking mechanism may also be used in the selective" type of vending machine where at the start of the vending cycle, all doors are locked and all compartments of the machine are loaded with merchandise, including those which are in the delivery position in line with the sill 150.

Each of the locking mechanisms 162 includes a lever arm 164 mounted on a pivot pin 166 for pivotal movement between a locking position and an unlocked position. When in the locked position, the lower end of the lever arm is adjacent the top end of the window panel 120 so that the window panel cannot be raised, and when the lever arm 164 is in its unlocked position, the lower end is swung away from the panel 120, and the panel 120 may be then raised without interference from the lever arm. The upper end of the lever arm 164 is connected to the operating arm 1680 of a solenoid 168 so that when the solenoid is actuated the operating arm 168a will be drawn inwardly to effect movement of the lever arm 164 to its open position. In FIG. 2 all of the locking mechanisms 162, with the exception of the locking mechanism associated with window 40d, are in a locked position. The locking mechanism associated with window 40a is in the unlocked position, permitting the window to be raised to its open position.

If the vending machine is a first-in and first-out type of unit, then suitable switches could be associated with the solenoid 168 or the lever arm 164 to prevent the operation of the motor 84 until the lever arm has been moved to its normal position, locking the window in its closed position.

The vending machine components are quite versatile, each being readily useable in various types and styles of machines. Certain of these components, such as the carrier-leveling means, may be modified in a number of ways. For example, a modified carrier-leveling mechanism 171 is illustrated in FIGS. 14-16. This carrier-leveling mechanism includes a follower 172 having a transverse carrier-engaging plate 174 which is pivotally connected to the two upright frame members 176 and 178 by means of integral arms 180 and 182. The plate 174 thus swings with the arms 180 and 182 about the horizontal axis of the pivotal connections of the arms to the frame members. The pivotal connection is such that the pivotal axis of the follower 172 is substantially horizontal and normal to the axes of pivotal connection of the carriers 78 to the conveyor chain arms 74a and 76a. The reciprocating movement of the plate, which is between the positions illustrated in FIGS. 15 and 16, is over a small angle and may be considered a generally vertical movement, and the portion of the plate 174 which engages the carriers 78 is horizontal in all positions of the follower movement. A coil spring 184 urges the follower into engagement with the carriers 78 as they are moved to the top of the rear portion of the conveyor run. As each carrier is moved about the end of the conveyor loop from the vertical rear portion of the conveyor run to the vertical forward portion of the conveyor run, the carrier-engaging plate 174 will be in constant engagement with the carrier and will maintain the top edges of the carrier in substantially horizontal orientation. in FIG. 15 the carrier 78 is shown as it has just moved to the top of the rear portion of the conveyor run and into engagement with the follower 172. In FIG. 16 the carrier is shown in its highest position at the very top of the conveyor loop. It will be noted that as the carriers 78 engage the follower, the follower merely swings in the clockwise direction about the pivotal connection with the frame. The follower is urged in the counterclockwise direction by the spring 184. The carrier leveling mechanism of FIGS. 14-16 is thus moved by the carriers and the movements are inherently synchronized. This type of carrier leveling mechanism requires sliding contact between the carriers and the carrier-engaging plate 174 of the follower, and, therefore, the undersurface of the carrier-engaging plate should be relatively friction free as should the top edges of the carriers so that there will be little frictional resistance to this sliding movement between these members. A similar leveling mechanism may be employed at the bottom of the conveyor loop; however, the spring urging the follower into engagement with the carriers at the bottom of the loop will have to support the weight of the follower.

In FIGS. 17-23 there is illustrated a carrier leveling mechanism 186 of modified construction which includes a follower 188 having an integral shank portion 190 and a head portion 192 having an inwardly directed flange portion 192a. The shank has a pair of slots 193 and 194 similar to the slots 103 and 104 in the follower shank portion 100 illustrated in FIG. 4. The follower and shank are, in fact, mounted precisely in the same manner as in the FIG. 4 embodiment with the end of the horizontal sprocket shaft 66 extending through the top slot 193 of the follower shank and the stud 108 extending through the lower slot 194 in the follower shank. In the embodiment of FIGS. 17-23, however, the top slot 193 is slightly longer in order to accommodate a stub shaft 196 (see FIG. 18) affixed to and protruding outwardly from the mounting plate 198. Exteriorly of the follower 188 on the end of the sprocket shaft 66 and keyed for rotation with that shaft is an elliptical gear 200. Mounted on the shaft 196 for free relative rotation with respect thereto is an eccentric idler gear 202 which is in meshing engagement with the elliptical gear 200, as best illustrated in FIG. 20. Fixed to the eccentric gear 202 for rotation therewith is an arm 204. A second arm 206 is pivotally connected to the distal or outer end of the arm 204 by means of a pin 208. The opposite end of the arm 206 is pivotally connected to the upper end of the follower 188 by means of a pin 210, and the end of the arm 206 is maintained in outwardly spaced relationship with respect to the follower by means of a spacer 212.

The idler gear 202 has one-half as many teeth as the elliptical gear 200 so that for each rotation of the elliptical gear 200, the eccentric idler gear 202 will rotate twice. This is necessary because for each l80 of rotation of the sprocket shaft 66 to which the elliptical gear 200 is keyed, the follower 188 must move upwardly and downwardly through a complete cycle. Thus, for each 360 of rotation of the sprocket shaft 66 and of the elliptical gear 200, the idler gear 202 must rotate twice, and the follower must go through two cycles of up and down movement.

The particular shape of the eccentric idler gear 202 is dependent upon the fact that this idler gear must remain in meshing contact with the elliptical gear 200 throughout the rotation of these two. The shape of the elliptical gear itself is governed by the fact that the follower does not move at a constant speed, for as previously indicated, the carriers 78 do not move in the vertical direction at a constant speed when they are moving about the top and bottom ends of the conveyor loops. Rather, these carriers move in the vertical direction at a higher speed when they are leaving the one vertical run and when they are coming into the other vertical run. At the top of the loop, the vertical speed of the carriers is the least. Of course, the carriers are moving at a constant peripheral speed, but the follower must be governed by the linear vertical speed of the carriers, and this is accomplished by means of the elliptical gear 200.

In the lowermost position of the follower illustrated in FIG. 21, the elliptical gear 200 has its major axes or longest dimension extending vertically, and in this position the elliptical gear is in meshing engagement with the shortest portion of the eccentric idler gear 202. The arm 204 of the idler gear 202 is pointing vertically downwardly in this starting or lowermost position of the follower 188. As the elliptical gear rotates through about one-sixth (30) of its required half turn cycle, the idler gear 202 will have made one-quarter of its required full turn cycle, and the gears will assume the position illustrated in F IO. 22.

As the elliptical gear moves through the next 60 to complete 90 of rotation, as illustrated in FIG. 23, the idler gear will again turn 90 to complete l80 of rotation. Since the arm 204 affixed to the idler gear 202 has been rotated 180 from its lowermost position illustrated in FIG. 21 to its uppermost position illustrated in FIG. 23, this will cause the follower 188 to be moved upwardly to its uppermost position because of the connection of the follower to the idler gear arm 204 through the connecting arm 206. As the elliptical gear 200 continues to rotate through the next 60 to complete of rotation of that gear and of the sprocket shaft 66, the idler gear 202 will rotate an additional 90 to complete 270 of rotation. For the final 30 of rotation of the elliptical gear 200 to complete its full l80 turn cycle, the idler gear 202 will turn another 90, thereby completing its 360 turn. It will be noted, however, that the speed of movement of the idler gear is greatest at the beginning and end of the 180 cycle of the elliptical gear, and the movement of the idler gear is slowest at the midpoint of that cycle.

It is to be understood that the present disclosure has been made only by way of example and that many additional modifications and changes in various details may be resorted to without departing from the invention.

What is claimed is:

1. In a vending machine, a cabinet having an opening, a plurality of product carriers, endless conveyor means movable about a closed loop including a pair of spaced, substantially vertical runs, means connecting said carriers to said conveyor means for pivotal movement about horizontal axes, whereby said carriers may be sequentially moved by said conveyor means to a discharge position in front of said cabinet opening, said carriers being so spaced and so proportioned that successive carriers are vertically juxtaposed and substantially in contact with each other to form a substantially uninterrupted column on the vertical runs of said conveyor means and are separated as they are moved about the ends of the conveyor loop, carrier leveling means for maintaining said carriers in substantially horizontal orientation as they are moved about one end of the conveyor loop from one vertical run to the other, a transparent viewing window mounted in registration with said cabinet opening for vertical sliding movement between an open and a closed position, said cabinet opening and said window being of a size to simultaneously expose to view the interiors of a plurality of product carriers on said one vertical run of said conveyor, and stop means for limiting the vertical movement of said window, whereby when said window is open the opening will give access to the interior of only that carrier which is in the discharge position.

2. The structure of claim 1 wherein carrier leveling means is provided at both the top and bottom ends of the conveyor loop, whereby said carriers will be maintained in substantially horizontal orientation as they are moved about the two ends of the conveyor loop.

3. The structure of claim 1 wherein said conveyor means includes a plurality of pairs of parallel carriersupporting arms extending outwardly substantially normal to the direction of conveyor travel, each of said carriers being carried by trunnion means between said arms.

4. The structure of claim 1 wherein said carriers each have a plurality of horizontal article supports, whereby the interior of each carrier is divided into a plurality of vertically adjacent compartments.

5. The structure of claim 1 wherein said carriers each have at least one vertical partition dividing the interior of said carriers into a plurality of laterally adjacent compartments.

6. The structure of claim 1 wherein said conveyor means includes at least two vertically aligned sprockets respectively defining the top and bottom ends of the conveyor loop, said sprockets being rotatable about parallel horizontal axes, and endless chain trained about said sprockets, a drive wheel rotatable about a general horizontal axis, said wheel having a plurality of rollers disposed in uniform radial array and mounted with their axes oriented generally parallel to the axis of rotation of said wheel, said rollers being in meshing engagement with one of said sprockets, and power means for rotating said drive wheel whereby said one sprocket may be rotated to drive said endless chain.

7. The structure of claim 6 wherein there are provided a pair of spaced parallel wheels with said rollers disposed therebetween.

8. The structure of claim 1 wherein the product carriers are arranged on said conveyor means to provide a plurality of laterally adjacent compartments which may be sequentially moved by said conveyor means to a discharge position, and there are a plurality of transparent viewing windows, one for each of said compartments.

9. The structure of claim 8 wherein locking means is provided for each of said windows, and means is pro vided for unlocking a selected one of said windows to give access to the carrier which is in the discharge position on the conveyor associated with that window.

10. The structure of claim 8 wherein said stop means is adjustable, whereby the maximum opening for each window may be regulated in accordance with the spacing between the product carrying portions of the carriers on the conveyor associated with that window.

11. The structure of claim 1 wherein there is provided at least one pair of hingedly interconnected arms, one of said arms being pivotally connected to a fixed pivot on said cabinet above the opening and the other of said arms being pivotally connected to a fixed pivot on said window, said arms being angularly disposed with respect to each other in all positions of said window movement, and resilient means urging said arms in a direction which will increase with the angle between said arms, whereby said window is urged toward its closed position.

12. The structure of claim 1 wherein there are two pair of hingedly interconnected arms, one arm of each pair being pivotally connected to said cabinet above the opening and the other arm of each pair being pivotally connected to said window, the arms of each pair being angularly disposed with respect to each other in all positions of said window movement, with the hinged angles of the pairs being opposite and equal, and resilient means urging said hinge connections toward each other, whereby said window is urged toward its closed position.

13. The structure of claim 12 wherein said arms are of equal length, and said two pairs of hingedly interconnected arms are pivotally connected to each other at the top and bottom to form a rhombic frame.

14. The structure of claim 13 wherein a spring extends between said hinge connections to resiliently resist their movement away from each other during movement of said window toward its open position.

15. In a vending machine, a cabinet having an opening, a plurality of product carriers, means for moving said carriers sequentially into a position of alignment with said opening for discharge, a panel for said opening, said panel being mounted for sliding movement between a closed position and an open position giving access to the interior of the carrier which is in position for discharge, and at least one pair of hingedly interconnected arms, one of said arms being pivotally connected to a fixed pivot point on said cabinet and the other of said arms being pivotally connected to a fixed pivot point on said panel, said arms being angularly disposed with respect to each other in all positions of said window movement, and resilient means urging said arms in a direction which will increase the angle between said arms, whereby said panel is urged toward its closed position.

16. The structure of claim 15 wherein there is a second pair of hingedly interconnected angularlydisposed arms pivotally connected to said cabinet and said panel, the hinge angles of said pairs of arms being equal and opposite in all positions of panel movement.

17. lna vending machine, a plurality of product carriers, endless conveyor means movable about a closed loop including a pair of spaced, substantially vertical runs, means connecting said carriers to said conveyor means for pivotal movement about horizontal axes which are fixed with respect to said conveyor means, whereby said carriers may be sequentially moved by said conveyor means to a discharge position, said carriers being so spaced and so proportioned that successive carriers are vertically juxtaposed and substantially in contact with each other to form a substantially uninterrupted column on the vertical runs of said conveyor means and are separated as they are moved about the ends of the conveyor loop, carrier leveling means for maintaining said carriers in substantially horizontal orientation as they are moved about one end of the conveyor loop from one vertical run to the other; said carrier leveling means comprising a follower member mounted for reciprocating movement in a generally vertical direction and having a transverse element positioned for engagement by said carriers as they are moved about the one end of the conveyor loop, and means for maintaining the carrier-engaging portion of said follower member transverse element in a substantially horizontal orientation throughout the movement of said follower member.

18. The structure of claim 19 wherein there is provided means synchronized with said conveyor means for forcibly moving said follower member and maintaining the carrier-engaging portion of said follower member normally in vertically-spaced relationship with respect to each carrier as that carrier is moved about the end of the conveyor loop, whereby a carrier will only engage said follower member portion if that carrier swings from its horizontal orientation as it is being moved about the end of the conveyor loop.

19. In a vending machine, a cabinet having an opening, a plurality of product carriers, means for moving said carriers sequentially into a position of alignment with said opening for discharge, and a transparent window for said opening, said window being mounted for sliding movement between a closed position and an open position giving access to the interior of the carrier which is in position for discharge, said cabinet opening and said window being of a size sufficient to simultaneously expose to view the interiors of several of said carriers including the carrier in said position for discharge.

20. The structure of claim 1 wherein said carrier leveling means includes a follower having a transverse element positioned for engagement by said carriers as they are moved about the one end of the conveyor loop, said follower member being mounted for pivotal movement about an axis which is substantially horizontal and normal to the axes of said means connecting said carriers to said conveyor means.

21. The structure of claim 19 wherein said carriers are vertically juxtaposed and substantially in contact with each other to form a substantially uninterrupted column from the time they are moved into view through said transparent window to after they have been positioned in alignment with said opening for discharge.

22. In a vending machine, a plurality of product carriers, endless conveyor means movable about a closed loop including a pair of spaced, substantially vertical runs, means connecting said carriers to said conveyor means for pivotal movement about horizontal axes, whereby said carriers may be sequentially moved by said conveyor means to a discharge position, carrier leveling means for maintaining said carriers in substantially horizontal orientation as they are moved about one end of the conveyor loop from one vertical run to the other; said carrier leveling means comprising a follower member mounted for reciprocating movement in a generally vertical direction and having a transverse element positioned for engagement by said carriers as they are moved about the one end of the conveyor loop, means for maintaining the carrier-engaging portion of said follower member transverse element in a substantially horizontal orientation throughout the movement of said follower member, and means synchronized with said conveyor means for forcibly moving said follower member and maintaining the carrier-engaging portion of said follower member normally in vertically-spaced relationship with respect to each carrier as that carrier is moved about the end of the conveyor loop, whereby a carrier will only engage said follower member portion if that carrier swings from its horizontal orientation as it is being moved about the end of the conveyor loop.

23. The structure of claim 22 wherein said means for forcibly moving said follower member includes an actuating element having a pair of oppositely-disposed arms, means for rotating said element about a transverse horizontal axis in synchronization with said conveyor means, said arms being sequentially movable into engagement with said ollower member, to urge said follower member away from the rotational axis of said element, and resilient means urging said follower member toward the rotational axis of said element.

24. The structure of claim 23 wherein said follower has an elongated shank portion mounted for vertical sliding movement laterally adjacent said conveyor means and the path of carrier movement, and a horizontally-disposed carrier engaging plate extending inwardly into the path of movement of said carriers about the end of the conveyor loop.

25. The structure of claim 23 wherein said follower is provided with a second horizontal portion positioned for engagement by the arms of said actuating element.

26. The structure of claim 25 wherein each of said actuating element arms carries a roller which is adapted to engage said follower member second horizontal portion.

27. The structure of claim 25 wherein said conveyor means includes a member rotatable about a horizontal axis and defining one end of said conveyor loop, said actuating element being affixed to and rotatable with said member.

28. The structure of claim 23 wherein said means for forcibly moving said follower member includes gear means operatively connected to said follower and driven in synchronization with said conveyor means.

29. The structure of claim 23 wherein said means for forcibly moving said follower member includes an operating member rotatable about a horizontal axis, an arm having one end pivotally connected to said follower member and the other end pivotally connected to said rotatable operating member, and means rotating said operating member in synchronization with the movement of said carriers about the end of the conveyor loop.

30. The structure of claim 29 wherein said rotatable member includes an eccentric gear and said means for rotating said rotatable member includes an elliptical gear in meshing engagement with said eccentric gear.

31. The structure of claim 30 wherein said conveyor means includes a rotatable guide member affixed to a horizontal shaft rotatable and defining one end of said conveyor loop, said elliptical gear being affixed to said shaft and rotatable with said guide member.

32. The structure of claim 30 wherein said conveyor means includes a pair of coaxially aligned rotatable sprockets, a pair of endless chains trained about said sprockets to define one end of said conveyor loop, said sprockets and said elliptical gear being keyed to a single shaft, whereby said elliptical gear will rotate with said sprockets in synchronization with said conveyor chains.

II i i l UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 697 148 Dated October 10, 1972 Inventor(s) Carl Weber It is certified that error appears in the aboveidentified patent .uul that am id Letters Patent are hereby corrected as shown below:

Column 16, line 64, "19" should be 17 Column 18, line 25, "25" should be 23 line 30, "23" should be 22 and line 34, "23" should be 22 Signed and sealed this 1st day of May 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents CRM PO-IOSO 110-6 USCOMM-DC B0376-P69 U 5 GOVERNMENT PRINYING OFFICE I 1969 0-366-33. 

1. In a vending machine, a cabinet having an opening, a plurality of product carriers, endless conveyor means movable about a closed loop including a pair of spaced, substantially vertical runs, means connecting said carriers to Said conveyor means for pivotal movement about horizontal axes, whereby said carriers may be sequentially moved by said conveyor means to a discharge position in front of said cabinet opening, said carriers being so spaced and so proportioned that successive carriers are vertically juxtaposed and substantially in contact with each other to form a substantially uninterrupted column on the vertical runs of said conveyor means and are separated as they are moved about the ends of the conveyor loop, carrier leveling means for maintaining said carriers in substantially horizontal orientation as they are moved about one end of the conveyor loop from one vertical run to the other, a transparent viewing window mounted in registration with said cabinet opening for vertical sliding movement between an open and a closed position, said cabinet opening and said window being of a size to simultaneously expose to view the interiors of a plurality of product carriers on said one vertical run of said conveyor, and stop means for limiting the vertical movement of said window, whereby when said window is open the opening will give access to the interior of only that carrier which is in the discharge position.
 2. The structure of claim 1 wherein carrier leveling means is provided at both the top and bottom ends of the conveyor loop, whereby said carriers will be maintained in substantially horizontal orientation as they are moved about the two ends of the conveyor loop.
 3. The structure of claim 1 wherein said conveyor means includes a plurality of pairs of parallel carrier-supporting arms extending outwardly substantially normal to the direction of conveyor travel, each of said carriers being carried by trunnion means between said arms.
 4. The structure of claim 1 wherein said carriers each have a plurality of horizontal article supports, whereby the interior of each carrier is divided into a plurality of vertically adjacent compartments.
 5. The structure of claim 1 wherein said carriers each have at least one vertical partition dividing the interior of said carriers into a plurality of laterally adjacent compartments.
 6. The structure of claim 1 wherein said conveyor means includes at least two vertically aligned sprockets respectively defining the top and bottom ends of the conveyor loop, said sprockets being rotatable about parallel horizontal axes, and endless chain trained about said sprockets, a drive wheel rotatable about a general horizontal axis, said wheel having a plurality of rollers disposed in uniform radial array and mounted with their axes oriented generally parallel to the axis of rotation of said wheel, said rollers being in meshing engagement with one of said sprockets, and power means for rotating said drive wheel whereby said one sprocket may be rotated to drive said endless chain.
 7. The structure of claim 6 wherein there are provided a pair of spaced parallel wheels with said rollers disposed therebetween.
 8. The structure of claim 1 wherein the product carriers are arranged on said conveyor means to provide a plurality of laterally adjacent compartments which may be sequentially moved by said conveyor means to a discharge position, and there are a plurality of transparent viewing windows, one for each of said compartments.
 9. The structure of claim 8 wherein locking means is provided for each of said windows, and means is provided for unlocking a selected one of said windows to give access to the carrier which is in the discharge position on the conveyor associated with that window.
 10. The structure of claim 8 wherein said stop means is adjustable, whereby the maximum opening for each window may be regulated in accordance with the spacing between the product carrying portions of the carriers on the conveyor associated with that window.
 11. The structure of claim 1 wherein there is provided at least one pair of hingedly interconnected arms, one of said arms being pivotally connected to a fixed pivot on said cabinet above the opening and the Other of said arms being pivotally connected to a fixed pivot on said window, said arms being angularly disposed with respect to each other in all positions of said window movement, and resilient means urging said arms in a direction which will increase with the angle between said arms, whereby said window is urged toward its closed position.
 12. The structure of claim 1 wherein there are two pair of hingedly interconnected arms, one arm of each pair being pivotally connected to said cabinet above the opening and the other arm of each pair being pivotally connected to said window, the arms of each pair being angularly disposed with respect to each other in all positions of said window movement, with the hinged angles of the pairs being opposite and equal, and resilient means urging said hinge connections toward each other, whereby said window is urged toward its closed position.
 13. The structure of claim 12 wherein said arms are of equal length, and said two pairs of hingedly interconnected arms are pivotally connected to each other at the top and bottom to form a rhombic frame.
 14. The structure of claim 13 wherein a spring extends between said hinge connections to resiliently resist their movement away from each other during movement of said window toward its open position.
 15. In a vending machine, a cabinet having an opening, a plurality of product carriers, means for moving said carriers sequentially into a position of alignment with said opening for discharge, a panel for said opening, said panel being mounted for sliding movement between a closed position and an open position giving access to the interior of the carrier which is in position for discharge, and at least one pair of hingedly interconnected arms, one of said arms being pivotally connected to a fixed pivot point on said cabinet and the other of said arms being pivotally connected to a fixed pivot point on said panel, said arms being angularly disposed with respect to each other in all positions of said window movement, and resilient means urging said arms in a direction which will increase the angle between said arms, whereby said panel is urged toward its closed position.
 16. The structure of claim 15 wherein there is a second pair of hingedly interconnected angularly-disposed arms pivotally connected to said cabinet and said panel, the hinge angles of said pairs of arms being equal and opposite in all positions of panel movement.
 17. In a vending machine, a plurality of product carriers, endless conveyor means movable about a closed loop including a pair of spaced, substantially vertical runs, means connecting said carriers to said conveyor means for pivotal movement about horizontal axes which are fixed with respect to said conveyor means, whereby said carriers may be sequentially moved by said conveyor means to a discharge position, said carriers being so spaced and so proportioned that successive carriers are vertically juxtaposed and substantially in contact with each other to form a substantially uninterrupted column on the vertical runs of said conveyor means and are separated as they are moved about the ends of the conveyor loop, carrier leveling means for maintaining said carriers in substantially horizontal orientation as they are moved about one end of the conveyor loop from one vertical run to the other; said carrier leveling means comprising a follower member mounted for reciprocating movement in a generally vertical direction and having a transverse element positioned for engagement by said carriers as they are moved about the one end of the conveyor loop, and means for maintaining the carrier-engaging portion of said follower member transverse element in a substantially horizontal orientation throughout the movement of said follower member.
 18. The structure of claim 19 wherein there is provided means synchronized with said conveyor means for forcibly moving said follower member and maintaining the carrier-engaging portion of said follower member normally in vertically-spaceD relationship with respect to each carrier as that carrier is moved about the end of the conveyor loop, whereby a carrier will only engage said follower member portion if that carrier swings from its horizontal orientation as it is being moved about the end of the conveyor loop.
 19. In a vending machine, a cabinet having an opening, a plurality of product carriers, means for moving said carriers sequentially into a position of alignment with said opening for discharge, and a transparent window for said opening, said window being mounted for sliding movement between a closed position and an open position giving access to the interior of the carrier which is in position for discharge, said cabinet opening and said window being of a size sufficient to simultaneously expose to view the interiors of several of said carriers including the carrier in said position for discharge.
 20. The structure of claim 1 wherein said carrier leveling means includes a follower having a transverse element positioned for engagement by said carriers as they are moved about the one end of the conveyor loop, said follower member being mounted for pivotal movement about an axis which is substantially horizontal and normal to the axes of said means connecting said carriers to said conveyor means.
 21. The structure of claim 19 wherein said carriers are vertically juxtaposed and substantially in contact with each other to form a substantially uninterrupted column from the time they are moved into view through said transparent window to after they have been positioned in alignment with said opening for discharge.
 22. In a vending machine, a plurality of product carriers, endless conveyor means movable about a closed loop including a pair of spaced, substantially vertical runs, means connecting said carriers to said conveyor means for pivotal movement about horizontal axes, whereby said carriers may be sequentially moved by said conveyor means to a discharge position, carrier leveling means for maintaining said carriers in substantially horizontal orientation as they are moved about one end of the conveyor loop from one vertical run to the other; said carrier leveling means comprising a follower member mounted for reciprocating movement in a generally vertical direction and having a transverse element positioned for engagement by said carriers as they are moved about the one end of the conveyor loop, means for maintaining the carrier-engaging portion of said follower member transverse element in a substantially horizontal orientation throughout the movement of said follower member, and means synchronized with said conveyor means for forcibly moving said follower member and maintaining the carrier-engaging portion of said follower member normally in vertically-spaced relationship with respect to each carrier as that carrier is moved about the end of the conveyor loop, whereby a carrier will only engage said follower member portion if that carrier swings from its horizontal orientation as it is being moved about the end of the conveyor loop.
 23. The structure of claim 22 wherein said means for forcibly moving said follower member includes an actuating element having a pair of oppositely-disposed arms, means for rotating said element about a transverse horizontal axis in synchronization with said conveyor means, said arms being sequentially movable into engagement with said follower member, to urge said follower member away from the rotational axis of said element, and resilient means urging said follower member toward the rotational axis of said element.
 24. The structure of claim 23 wherein said follower has an elongated shank portion mounted for vertical sliding movement laterally adjacent said conveyor means and the path of carrier movement, and a horizontally-disposed carrier engaging plate extending inwardly into the path of movement of said carriers about the end of the conveyor loop.
 25. The structure of claim 23 wherein said follower is provided with a second horizontal portion pOsitioned for engagement by the arms of said actuating element.
 26. The structure of claim 25 wherein each of said actuating element arms carries a roller which is adapted to engage said follower member second horizontal portion.
 27. The structure of claim 25 wherein said conveyor means includes a member rotatable about a horizontal axis and defining one end of said conveyor loop, said actuating element being affixed to and rotatable with said member.
 28. The structure of claim 23 wherein said means for forcibly moving said follower member includes gear means operatively connected to said follower and driven in synchronization with said conveyor means.
 29. The structure of claim 23 wherein said means for forcibly moving said follower member includes an operating member rotatable about a horizontal axis, an arm having one end pivotally connected to said follower member and the other end pivotally connected to said rotatable operating member, and means rotating said operating member in synchronization with the movement of said carriers about the end of the conveyor loop.
 30. The structure of claim 29 wherein said rotatable member includes an eccentric gear and said means for rotating said rotatable member includes an elliptical gear in meshing engagement with said eccentric gear.
 31. The structure of claim 30 wherein said conveyor means includes a rotatable guide member affixed to a horizontal shaft rotatable and defining one end of said conveyor loop, said elliptical gear being affixed to said shaft and rotatable with said guide member.
 32. The structure of claim 30 wherein said conveyor means includes a pair of coaxially aligned rotatable sprockets, a pair of endless chains trained about said sprockets to define one end of said conveyor loop, said sprockets and said elliptical gear being keyed to a single shaft, whereby said elliptical gear will rotate with said sprockets in synchronization with said conveyor chains. 